The Zork source code is good for learning, is there others?

Unfortunately they’re both written for very old versions of I7, now. Reliques’ source was published a bit before I7 was made publically available, and I’m not sure it has ever been compilable as published in a public version of I7. It’s possible to convert them (I’ve made a working copy of Reliques, for instance) but that’s probably a quagmire for a new learner.

Last year I finished a conversion of Crowther’s original, pre-Woods version of Adventure into I7, and one goal of that project was to produce a legible source for writers to learn from. I’ve been putting off releasing a new bug-fix version until the big new I7 release – this seemed like a more reasonable plan last year – but the version available in that thread still compiles in 6G60.